Though not illustrated, a conventional substrate storage container for accommodating semiconductor wafers comprises a front open box container body for accommodating a plurality of thin semiconductor wafers of φ300 mm in alignment and a door that is detachably attached to open and close the open front of this container body. The container body is injection-molded using molding material including resin, on the assumption that semiconductor wafers having a thickness of 700 to 800 μm are accommodated. Provided on the inner surface of both side-walls are plural pairs of left and right teeth, each integrally formed for horizontally supporting a semiconductor wafer and arranged vertically with a predetermined pitch (see Patent Documents 1, 2, 3, 4, 5 and 6).
Each pair of teeth are horizontally projected inwards from the inner surface of the side-walls of the container body so that each forms an elongate plate piece extending from the front to rear of the container body with its rear part gradually narrowed as it goes to the rear of the container body, and function to support a semiconductor wafer from the bottom at around the areas of the peripheral edge thereof, located across the maximum diameter from one side to the other. The semiconductor wafer thus supported by these teeth is put in and taken out by a dedicated robot.
However, recently, in order to improve productivity and enlarge the chip size in conformity with enlargement of memory capacity, φ450 mm semiconductor wafers have been studied and internationally discussed as a next generation type after the φ300 mm type. With increased discussion of this, substrate storage containers configured to support the large-diametric semiconductor wafers have become demanded.